Reading DTS in PCM on an amplifier that doesn't decode it.

Hello,

I wanted to ask a question to the home theater enthusiasts and professionals.

So I have a problem with an amplifier that was given to me recently; it easily decodes Dolby Digital but lacks the DTS codec (amp from the 2000/2001 era), and that's a shame given the films and HD masters that directors are producing these days.

So I've come up with this hypothesis, since this amp has sentimental value for me and considering the prices of these devices, what if I read the DTS by going through PCM?
I know that PCM is a lossless, uncompressed source.

I've done my research online, but since I don't want to buy a device for nothing, I'm asking the question to the experts.

I found this: https://www.cdiscount.com/high-tech/accessoires/adaptateur-convertisseur-hdmi-vers-rca-audio-co/f-1062802-auc8800201706822.html

If I output from my Blu-ray player to the only HDMI input on the box and then output via optical or coaxial into the amp (which doesn't have HDMI), will my sound be in PCM and 5.1?
Or are there other solutions?

Thank you.